1. The Field of the Invention
The present invention relates to systems and methods for intra-frame video error concealment. More specifically, the present invention is directed to systems and methods for concealing a video error segment located in a frame of a static or moving image by utilizing an intra-frame concealment technique that selectively rotates, weights and adds pixels to diminish the visual impact of the error segment, thereby eliminating video discontinuities on which a viewer may focus.
2. The Prior State of the Art
With the development of electronic media such as television and computers, current technology allows static and/or moving images to be displayed on a display device. Generally, the images are represented by electronic video data that may be stored, duplicated, transmitted, manipulated, processed, compressed, and/or deleted. Scanners, cameras, recorders, drawing applications, and the like generate the video data corresponding to the displayed images.
A portion of the video data representing an image can become lost or corrupt, causing an error segment to appear in the displayed image. The error segment is a noticeable distraction for a viewer and can vary in its size and shape. Furthermore, the data loss can propagate and become even more rampant in moving images where future frames depend on the frame that contains the error segment. This error propagation causes the visual distraction to be even more noticeable to a viewer.
Current techniques used to remedy data loss and error propagation include utilizing data from another frame to conceal the error segment, employing an auto-regressive model to interpolate missing video data, and using a motion compensated error concealment technique. In utilizing data from another frame, the video data corresponding to the same location in the present frame where the error segment resides is taken from a previous frame and is used to replace the erroneous data. In the auto-regressive technique, a linear interpolation is required that is computationally expensive. In the motion compensated error concealment technique, motion vectors are utilized from previous or subsequent frames to replace the error segment and can become computationally complex. Each of the current concealment techniques allows discontinuity to exist in the static or moving image. The discontinuity is generally created at the boundaries of the error segment that is being concealed. Furthermore, the discontinuity in moving images can propagate to future dependent frames.
The present invention relates to systems and methods for intra-frame video error concealment. More specifically, the present invention is directed to systems and methods for concealing a video error segment located in a frame of a static or moving image by utilizing an intra-frame concealment technique that selectively rotates, weights and adds pixels to diminish the visual impact of the error segment, thereby eliminating video discontinuities on which a viewer may focus, including the discontinuities that are experienced in association with conventional error concealment techniques. The intra-frame concealment methods can be used independently or in combination with conventional error concealment techniques, and can be used to conceal an error segment of any shape or location in a frame of a static or moving image.
To conceal an error segment, implementation of the present invention includes flipping a first set of pixels immediately adjacent to the error segment so that the first set of pixels is overlaid on the error segment. The flipped first set of pixels is then selectively weighted. When a second set of pixels adjacent to the error segment is available, the second set is also flipped so that the second set of pixels is overlaid on the error segment. The flipped second set of pixels is also selectively weighted. The first and second sets are then added together to create a sum set of pixels that replaces the pixels of the error to diminish the visual impact of the error segment, thereby eliminating video discontinuities that a viewer may focus on due to the error segment present in the frame.
The error concealment methods of the present invention can be used for error segments of various shapes, sizes, and/or locations in a frame. The pixel sets that are flipped onto the error segment are selected to cover the error segment. The flipping of adjacent pixels, combined with the selective weighting of the flipped pixels, has the advantage of producing a smooth transition between the sum set of pixels and the adjacent first and second sets of pixels without any distracting boundaries. The smooth transition is created because the pixels from the sum set are adjacent and identical, or nearly identical, to non-corrupt, non-modified pixels. The smooth transitions and the sum set of pixels eliminate the video error discontinuities that have been traditionally experienced from video error segments and traditional error concealment techniques.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The features and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.